Internet Service Providers are rolling out a wide range of value added services beyond basic connectivity, such as web hosting, content distribution network (CDN) service, database, gaming, cloud computing and e-commerce server hosting. These services have vast numbers of customers from throughout the Internet. They are typically hosted in geographically distributed data-centers that are often co-located with ISPs' Point of Presence (PoPs) and managed by the same ISPs. Detecting and localizing end-to-end performance issues in these wide area services is critical for ISP operators to improve the service quality perceived at wide-area end users, for example, through fast service impairment detection and flexible mitigation control.
Currently-used service performance monitoring approaches use large numbers of active probing devices strategically placed in the network. That approach has several disadvantages. First, the services may cover a vast number of users from diverse locations. Without active probes from a vast number of network locations throughout the Internet, the monitoring coverage is limited and some performance issues will not be detected. Second, even when performance issues are identified, the localization of the performance issues is limited by the number, source location and frequency of the probes. Finally, a significant number of probe packets place additional overhead on the network and may be treated differently than normal packets.